Crankcase ventilator



Patented June 3, 1941 U i T E STATES PATENT OFFICE r 3 Claims.

This invention relates to internal combustion engines and more particularly to a crank-case ventilator therefor.

In automotive practice crank-cases of motor vehicle engines are ventilated by inducing flow of vapors from the crank-case through a ventilator opening in a side thereof responsive to inducing action of air moving thereacross incidental to forward motion of the vehicle. It is therefore obvious that the amount of ventilation is governed by the velocity of the vehicle and such an arrangement is not eificient when the vehicle is travelling at low speeds as, for example, in the case of trucks, tractors, and similar low speed vehicles.

In recent years automotive engines are used as stationary engines and consequently the customary crank-case ventilation is practically useless with the result that the lubricating oil in such engines soon becomes so highly diluted that it is inefilcient as a lubricant, causing rapid Wear and deterioration of the engine. Fumes also escape through the ventilation opening and other parts of the crank-case which are hazard- Oils and highly objectionable.

It is, therefore, a principal object of the invention to provide a crank-case ventilator system especially adapted for use on stationary engines and the engines of slow operating vehicles such as tractors, trucks, and the like, whereby the crank-case vapors are positively removed and safely disposed through induction thereof into the combustion chambers of the engine.

Other objects of the invention are to provide a duct leading from the ventilating opening to the air intake of the carburetor; to provide connections for the duct that are readily adaptable to existing types of motor vehicle openings; and to provide the duct with means for disposing of condensation that may collect therein.

In accomplishing these and other objects of the invention, as hereinafter pointed out, I have provided improved details of structure, the preferred forms of which are illustrated in .the accompanying drawing, wherein:

Fig. l is a side elevational view of a conventional type motor vehicle engine equipped with a crankcase ventilator constructed in accordance with the present invention.

Fig. 2 is a vertical section through the collar which is interposed between the air intake of the carburetor and the air filter and to which the crank-case vapor conduction tube is connected.

Fig. 3 is a fragmentary elevational view of a portion of the motor vehicle engine particularly illustrating the ventilator opening of the crankcase and connection of the conducting tube therewith.

Fig. 4 is a fragmentary perspective viewof the part of the engine shown in Fig. 3 and showing the gasket ring and the conducting tube connection in disassembled spaced relation with the ventilator opening.

Fig. 5 is a view similar to Fig; 3 a modified form of the invention. 7

Referring more in detail to the drawing: I designates a conventional type of internal combustion engine which includes a block 2 having an upper portion 3 containing the engine cylinders and having a lower portion 4 forming the upper part of the crankcase 5.

Formed within a niche 6 of the crank-case 5 at the front thereof and opening into the upper portion of the crank-case is a vent opening 1. Ordinarily secured over this opening is an induction fitting that extends into the stream of air moving along the sides of the motor whenthe vehicle is in motion so that vapors are withdrawn from the crank-case incidental to the inducing action of the air.

The engine also includes a carburetor 8 having an air inlet 9 to which an air cleaner It is ordinarily connected, the air cleaner being provided with a depending annular flange II which telescopes over a reduced neck I2 of the air inlet to the carburetor.

As above pointed out, the crank-case ventilator is eflicient only when the motor .vehicle is in motion and operating at substantially rapid speed. In trucks and similar slow movingvehicles the induction action of the vehicle in motion is not sulfiicient to withdraw the vapors from the crank-case with the result that the vapors cause rapid dilution of the lubricating oil or they are discharged at such a slow rate through the ventilator opening that they are not carried away from the engine. The vapors therefore condense on the exterior surfacesof the engine and collect dust which forms an insulation resulting in higher working temperatures. Thevapors are also fire hazards and filter into the body of the vehicle so that they are objectionable to the occupants.

When automotive engines are used for stationary power the conventional ventilating system is practically useless and the above mentioned difficulties are aggravated. To overcome these diifficulties I have provided means for con-.- ducting vapors from the vent opening I to the air intake 9 of thecarburetor 8 so that the vapors are readily withdrawn fromthe crankcase and disposed by burning thereof in the combustion chambers of the engine.

In carrying out my invention, the conventional ventilator is removed from covering relation with the vent opening I and replaced with a special fitting I3. The fitting l3 includes a plate It having an interconnected socket I5 projecting but showing.

from the lower face thereof and provided with a channel I6 extending therethrough. The inlet of the channel substantially conforms in shape to the vent opening I and its outlet is of circular form and internally threaded, as at IT, to mount the end I8 of a flexible tube I9. The inlet of the fitting is recessed, as indicated at in Fig. 4, to accommodate a gasket ring 2I which seals the fitting with respect to the portion of the cylinder block surrounding the vent opening I to provide a leak-proof joint.

The plate portion of the fitting also includes an ear 22 and an angularly extending arm 23 on the opposite side which are provided with openings 24 and 25 registering with openings 26 and 21 in the rim of the crank-case 5 and aligning threaded openings 28 and 29 in the flange of the cylinder block. Fastening devices such as cap screws 30-and 3I are projected through the openings 25 and 26 and turned into the threaded openings 28 and 29 to secure the fitting in position as shown in Fig. 3. The flexible tube I9 is preferably formed of a helical wound metal ribbon 32 having the edges offset and hooked together to provide flexibility and form a closed duct. The convolution-s at the end I8 of the tube l9 form threads which are engageable with the internal threads I! of the fitting. After thread ing the conduit into the fitting it is preferably pinned therein as indicated at 33. The conduit is ofsufiicient length to extend to the air intake of the carburetor and has its opposite end threaded into. and secured by a pin 34 in a lateral connection 35 on a collar 36.

The collar 36 has a socket 3! to receive the reduced neck I2 of the air inlet of the carburetor and a reduced neck 38 over which the flange II of the air cleaner is sleeved as shown in Fig. 2. The collar is retained on the reduced neck of the air'intake by a set screw 39 threaded into the collar and having the end thereof engaged in an external annular groove 40 of the air inlet. The neck 38 of the collar is provided with an outside groove 4! to be engaged by a fastening device (not shown) which secures the air cleaner thereon. When the conduit is applied to an engine as shown in Fig. 1, the lower end thereof falls in a curve 42 and condensation is likely to collect therein when the motor is idle. To eliminate this. condensation thisportion of the conduit is provided with a series of drain openings 43 in the bottom side thereof as shown in Fig. 3.

With the engine in operation, a portion of the air delivered to the carburetor is drawn from the crankcase through the flexible tube so that the vapors are carried therewith and mixed with the air moving through the collar 36 from the air cleaner for delivery with the fuel charge into the combustion cylinders of the engine. The vapors are thus positively drawn from the crankcase under suction of the engine and disposed of by burning in the combustion chambers regardless of the speed at which the vehicle is in motion, consequently my invention is particularly adapted to engines of motor trucks. tractors, and similar slow moving automotive vehicles. It is also adapted for ventilation of the crank-case of an automotive engine when the engine is used for stationary power purposes.

In the form of the invention shown in Fig. 5, the flexible tube is in separate sections 44 and 45, interconnected by a sleeve 46 having a port 41 which is normally closed by a valve 48. The valve 48 is retained against its seat by a spring 49 having one end seated in an annular recess 50 of the sleeve and its opposite end bearing against a washer 5| carried on the stem 52 of the valve. The spring is of light tension and is only suflicient to retain the valve closed. Ordinarily the suction effected in the conduit retains the valve closed when the motor is in operation.

When the motor is idle, the valve may drop open sufficiently to allow escape of any condensation that may take place.

From the foregoing it is obvious that I have provided a ventilator which is readily adapted to the ventilating system of an automotive engine so that positive ventilation is maintained at all times and the vapors collecting in the crank-case are disposed of by delivering them to the combustion cylinder. It is further obvious that a slight vacuum is maintained in the crankcase so as to retard leakage of oil therefrom, thereby lowering the oil consumption. Also by passing the crank-case vapors into the combustion cylinders, top lubrication is provided to prolong the life of the engine cylinders. The engine equipped with a ventilator as described, is also kept in'clean, dry condition, with the result that it operates at lower working temperatures. This is especially advantageous when the engine is used for stationary power purposes.

What I claim and desire to secure by Letters Patent is:

1. In combination with an engine having an outlet in the front of the crank-case by which air is ordinarily drawn through the crank-case by air passing over said outlet incidental to movement of air along the sides of the engine, and having a carburetor supplying a carbureted mixture to the engine cylinders and provided with an air inlet and an air cleaner. of means for maintaining said air movement through the outlet when the engine is used as a stationary engine, including a collar connecting the air cleaner with the air inlet of the carburetor and having, a lateral port, a fitting connected with said outlet, and a conduit connecting the fitting with the lateral port of the collar whereby suction is maintained at said outlet by way of suction through the carburetor of the engine.

2. In an engine having a downwardly facing vent opening in the crank-case thereof and a carburetor supported above the engine for supplying a carbureted mixture to the cylinders of the engine and provided with an air inlet, a fitting connected with said vent opening, and a flexible conduit connecting, the fitting with the air inlet of the carburetor and havinga sag in the end connected with the fitting whereby the end of the conduit registers with the downwardly facing vent opening, said sag of the conduit having an opening in the lowermost portion for draining condensation from said conduit.

3. In an engine having a downwardly facing vent opening in the crank-case thereof and a carburetor supported above the engine for supplying a carbureted mixture to the cylinders of the engine and provided with an air inlet, a fitting connected with said vent opening, a flexible conduit connecting the fitting with the air inlet of the carburetor and having a sag in the end connected with the fitting whereby the end of the conduit registers with the downwardly facing vent opening, and a condensation release valve in the sag of said conduit.

ARTHUR J. ROOT. 

